Can't offer any help on your first question, except to say that "mobile versions" aren't necessary in this day and age; with all the responsive design tools (look up bootstrap or foundation to get started) and ever increasing support for html5...
In regards to your second question, we use this script:
http://code.google.com/p/php-mobile-detect/ for the small mobile detection we need (like disabling some js/jquery stuff in mobile browsers) and it works really well. With that script, all you would need to do is header redirect via php if the detection returns false...